This invention relates to multilayer metal foil insulating and shielding products which have both thermal and acoustical insulation and shielding utilities.
Multilayer metal foil products are known in the art for heat and acoustical insulation and shielding. One class of such products are generally known as xe2x80x9call metalxe2x80x9d shielding and insulation products made from multiple layers of metal foils. Although referred to as all metal heat shields and heat insulation products, it is commonly understood that such products may contain various other materials interspersed between the foil layers such as fibers, adhesives, scrim layer and the like. An example of all metal heat shields is disclosed in U.S. Pat. No. 5,800,905 which discloses multiple layers of metal foils configured in spaced apart layers to provide heat shielding products for the automotive industry and other uses. Another example of such products is disclosed in U.S. Pat. No. 5,958,603 which is directed to similar multilayer metal foil heat shield and insulation products but which are formed as integral products having independent structural strength due to structural features such as a rolled edge which combines all the layers into a fixed rigid structural configuration. Another example of similar multilayer metal products is disclosed in U.S. Pat. No. 5,939,212 which is directed to multilayer metal foil products which are corrugated in nature and which may be formed into flexible or stand-alone structural members by interlocking the corrugations of the multiple metal foil layers together. Multilayer metal foil heat insulation and shielding members are also useful in the food preparation devices, such as those illustrated in U.S. Pat. No. 5,406,930 and in pending U.S. patent application Ser. No. 09/422,140. The disclosures of the above patents and patent application are incorporated herein by reference in their entirety.
Another category of multilayer metal foil heat insulation and shielding products are those which include as a significant or major portion of the layered product fibrous insulation materials. Examples of these multilayer metal foil products containing layers of fibrous materials are shown in U.S. Pat. No. 5,658,634 and U.S. Pat. No. 5,767,024. Typically these types of multilayer metal foil shields having significant fiber content are used in lower temperature applications than the above xe2x80x9call-metalxe2x80x9d type products. The disclosures of the above patents are incorporated herein by reference in their entirety.
While the manufacture of the above multilayer metal foil insulation and shielding products is well-known, there is a need for increased efficiency and increased flexibility in the manufacturing processes which can be used for production of those products.
This invention provides new and improved manufacturing methods and manufacturing apparatus for production of multilayer metal foil insulation and shielding products. The present inventions are useful in the production of both the xe2x80x9call-metalxe2x80x9d type products as well as fiber containing products. The present inventions also include certain new and novel multilayer metal foil products themselves.
In one aspect this invention provides a method of forming a multilayer metal foil product comprising providing a continuous stack of metal foil layers; separating at least two of the layers of the stack; imparting a pattern or surface treatment to at least one of said separated layers of metal foil; recombining the separated metal foil layers into a continuous stack of metal foil layers; and forming and cutting individual multilayer metal foil parts from said recombined continuous stack of metal foil layers. In this method of the invention each layer of the stack of metal foils can be either smooth or can be individually previously patterned with embossments, corrugations or other desired patterns. In this method, the stack of metal foil layers is separated usually into individual layers for the purpose of treating each individual layer with either patterns, such as embossments or corrugations, or surface treatment of each layer such as with adhesives or other materials. Once the individual layers are patterned or treated as desired, the layers are recombined into the continuous stack of metal foil layers, which continuous stack is then used for forming and cutting individual multilayer metal foil parts and devices from the recombined continuous stack of metal foil layers. As will be recognized from the disclosure herein, the initial continuous stack of metal foil layers may also comprise intermediate layers of fiber material or other desired materials, or alternatively, once the individual metal foil layers are separated in the process of this invention, the additional layers, such as fiber layers can be inserted between the separated metal foil layers before the separated layers are recombined into the continuous stack of metal foil layers used for cutting and forming individual multilayer metal foil parts.
In another aspect of this invention an apparatus is provided for producing and a multilayer metal foil product comprising a separator for receiving a continuous multilayer stack of metal foil layers and separating at least two layers of said stack; a tool for imparting a pattern or surface treatment to at least one of said layers of metal foil; a feeder for feeding the separated layers through a slot for recombining the layers into a continuous multilayer stack of metal foil layers; and a second tool for receiving the recombined multilayer stack and for forming and cutting individual multilayer metal foil parts from said stack. The above apparatus is adapted to separate the layers of the metal foil stack, treat certain layers by surface treatment or patterns, such as embossments or corrugations, and recombining the layers into the stack of metal foil layers and finally, forming and cutting individual multilayer metal foil parts from the recombined stack of layers. The apparatus can optionally include additional intermediate feeder for inserting and feeding an additional layer of material into the stack between the separated layers before the separated layers are recombined into the continuous stack for forming and cutting individual parts from the stack.
In another aspect this invention provides a method of forming a multilayer metal foil product comprising providing a continuous stack comprising patterned and nested metal foil layers; separating at least two of the nested layers of the stack; recombining the separated metal foil layers into a continuous stack of the metal foil layers in a manner to prevent the layers from nesting; and forming and cutting individual multilayer metal foil parts from said recombined stack of metal foil layers. In this aspect of the invention, the nested preformed patterned layers are separated and recombined in a non-nested form to provide gaps between the metal foil layers before the multilayer stack is used to form and cut individual multilayer metal foil parts from the recombined stack of spaced apart metal foil layers. In this aspect of the invention, the continuous stack of patterned and nested metal foil layers is provided by combining multiple layers of smooth metal foil into a stack and then embossing or corrugating or otherwise forming a patterned texture in all of the layers of the stack at the same time, which results in the stack of patterned metal foil layers being nested. Such a stack of metal foil layers is then subjected to the above method of separating the layers and recombining the layers in a manner to prevent the layers from nesting. Such a method can include offsetting the patterns of each individual layer from the similar patterns of an adjacent layer to prevent the layers from nesting. Then the layers are recombined into the multilayer stack for forming and cutting individual multilayer metal foil parts from the recombined stack.
In another aspect, this invention provides apparatus for producing a multilayer metal foil product comprising a separator for receiving a continuous nested stack of patterned metal foil layers and separating at least two layers of said stack; a tool for offsetting the separated layers to prevent nesting of the layers when recombined into a stack; a feeder for feeding the separated layers through a slot for recombining the layers into a continuous stack of metal foil layers; and a second tool for receiving the recombined stack and for forming and cutting individual multilayer metal foil parts from said stack.
In another aspect, this invention provides a method of producing a multilayer metal foil product comprising combining a plurality of continuous metal foil layers to form an advancing continuous stack of metal foil layers; scoring or creasing the advancing continuous stack of metal foil layers across at least a portion of the width of the stack at predetermined intervals along the length of the continuous stack; causing the continuous stack of metal foil layers to fold in alternating directions at said scores or creases; and piling the alternately folding stack in a zigzag fashion to form a z-fold pack of the continuous stack of metal foil layers. In this aspect of the invention, the method is provided to provide a new form of feedstock for various operations manufacturing multilayer metal parts and products, particularly multilayer metal foil parts and products. Conventionally, such multilayer metal foil parts and products have been formed from multiple layers of metal foils where each layer of metal foil is supplied into the manufacturing process from a metal foil roll. The present method of this invention provides a method of making a multilayer metal foil raw material which can be supplied to manufacturing operations where multilayer metal foil parts and products are formed and shaped. The multilayer metal foil continuous stack formed into the z-fold pack according to this invention is useful in those manufacturing operations which are not equipped to handle rolls of individual metal foil layers.
In another aspect, this invention provides an apparatus for producing a multilayer metal foil product comprising a plurality of feeders for feeding a plurality of continuous metal foil layers to a collection slot; a collection slot positioned to receive the plurality of continuous metal foil layers therethrough to form a continuous multilayer stack of said metal foil layers and positioned to pass the continuous stack to a tool; a tool for receiving the continuous stack and laterally scoring or creasing the continuous stack of said layers across at least a portion of its width at predetermined intervals along its length and causing the continuous stack of said layers to fold in alternating directions at said intervals into a pile; and a support member positioned for receiving the pile of the folding continuous stack of said metal foil layers from said tool to form a z-fold pack of folded continuous stack of metal foil layers.
In another aspect, this invention provides a multilayer metal foil product comprising a plurality of continuous metal foil layers having a width X and formed in a multilayer stack wherein the continuous multilayer stack of metal foil layers is folded across width X at intervals Y in alternating directions, is piled in a zigzag fashion in the form of a pack of a continuous multilayer metal foil stack, said pack having a width X, a length Y and a height H determined by a preselected desired length of the z-folded continuous multilayer stack of metal foil layers or a preselected desire height of the z-fold pack to make it suitable for shipping and handling at the parts manufacturing operation.
In another aspect, this invention provides a method of producing multilayer metal foil parts comprising feeding to a parts forming operation a continuous multilayer stack of metal foil layers from a z-fold pack of a continuous multilayer stack of metal foil layers; and forming and cutting individual multilayer metal foil parts from said stack of metal foil layers.
The above aspects of this invention are more fully explained in reference to the drawings and general disclosure herein.